Of known types of nozzles, it is very difficult to effect a uniform spray of the fluid to be passed through the nozzle, e.g. gasoline in a carburetor nozzle, fuel oil in a burner nozzle, spraying liquid in a plant spray apparatus. These difficulties are accentuated particularly in nozzles of the kind where the nozzle orifice coacts with a valve body, the object of which may be to effect an adjustment of the flow amount through the nozzle, an atomization of the liquid or a combination of both adjustment and atomization.
The difficulty of obtaining an efficient operation with such a nozzle is due to the fact, that the valve body must assume a position centered accurately in relation to the nozzle orifice. At the slightest lateral displacement of the valve body, a larger amount of liquid will be sprayed in the direction of the widest annular gap between the valve body and the valve seat. When the annular gap, due to an unsatisfactory centering of the valve body, is able to vary from a position of the valve body abutting one side of the nozzle orifice, to a position of the valve body aligning with the center of the nozzle orifice, the adjustment function will be unstable. In spite of the fact, that the flow area in both said cases can be accurately equal, and all other circumstances, for example the pressure of the fluid supplied, can be identical, the flow amount knowingly will be much greater in the first mentioned case than in the last mentioned one.